Lens-drilling machine.



G. A. BADER .6. c.`w. HowLANn.

LENS DRILLING MACHINE.

PPLICATION HLED SEPT. 12. 1912.

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G. A. ,BADER al c; w. HowLAND. fLENS DRILL'ING MACHINE. -MucATloNmEr-1 SEPT. 12. 1912.

. Patented June 1, 1915.

5 SHEETS-SHEET 2.

G. A. BADER @L c. W. HowLAND.

LENS DRILLING MACHINE?.

APPLICATION P|| ED SEPT. t2, I rz. V

Patented June 1, 1915.

5 SHEETS-SHEET 4.

AG. A. BADER & C. W. HOWLAND.

LENS DRILLING MACHINE. APVPLICATION FILED SEPT. 12, 1912.

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GUSTAV A. BADER, F ROCHESTER, AND CHAUNCEY W. HOWLAND, OF GENEVA, NEW YORK, ASSIGNORS TO THE STANDARD OPTICAL COMPANY, OF GENEVA, NEW YORK A CORPORATION OF NEW YORK.

LENS-DRILLING MACHINE.

specification of Letters raten.

Patented Jane 1, 19'15.

Application led September 12, 1912. Serial No. 719,950.

To all whom it may concern Beit known that we, GUSTAV A. BADER -and GHAUNGEY W'. Hou/LAND, of Rochester' and Geneva, respectively, in the counties of Monroe and Ontario, respectively, in the State of New York, have invented new and useful Improvements in Lens-Drilling Machines, of which the following, taken in connection with the accompanying drawings, is a full, clear, and exact description.

This invention relates to certain improvements in lens drilling machines of the class set forth in the patent to C. W. Howland, #979,007, December 20, 1910, in so far as it relates broadly to a lens support which is adjustable horizontally and vertically to different angles relatively to the axis of a rotary and axially movable drill spindle and to adjustable stops for gaging the depth of the drill hole and its distance from-the edge of the lens.

In drilling lenses for the reception of mountings and for other purposes, it is customary to drill part way through the lens from one side and then to reverse the lens 'and drill from the opposite side until the drill point reaches the apex of the previously drilled hole, thus forming an aperture which is shaped somewhat like anihour-v glass or contracted at the meeting ends of the two drill holes after which the contracted portion is reamed and iinished to the desired size by means of a. reamer and frequently results in breaking away the adjacent portions of the lens between the hole and rim. liurthermore it sometimes happens through careless manipulation that the drill will be forced into thelens under es-L eess pressure suilicient to canse the lens to break or if a diamond drill is used to cause the breaking or chipping of the drill.

The main object, therefore, of our present invention is to provide a lens drilling machine by vwhich the holes for the mountings may be easily and quickly drilled from op` posite sides of the lens with perfect accuracy to finish the hole with the drill without vthe additional operation of reaming and without liability of breaking either the lens er drill even in the hands of unskilled or careless operators.

Another object is to enable the lens holder with the lens thereon to be adjusted horizontally so as to bring the mechanical' axis of the lens to the same angle at either side of its neutral position by a single gage setting of the lens holder so that when the lenssupport is set to drill a lens part-way through from one side a predetermined dis-v tance oiicenter, such lens may be reversed in the holder and the latter adjusted angu lai-ly in the opposite direction until automatically stopped and then redrilled from the opposite side with theassurance that the two drill h oles from opposite sides will be in exact alineinent.

Another object is to provide the machine with a multiple stop gage cooperating with one of the movable operating parts for re. ciprocating the drill,.whereby lenses of ldifierent thicknesses may be drilled the proper distance through from one side by simply adjusting' the stop gage so as to bring its particular stop corresponding to ythe gage of the lens into registration with the cooperative stop on thc reciprocating drill supporting frame.

Another object is to obyiate as far as possible the use of screws and similar fastening` means in assembling the various parts of the lens support and its cooperating adjuncts.

Other objects and uses relating to specific parts of the machine will be brought out in the following description.

ln the drawings Figure l is a front eleation of a lens drilling machine embodying the various features of our invention. Fig. i2 is a side elevation of the mechanism shown in Fig. l, except vthat the lower portion of the standard is broken away. Fig. 3 is a transverse vertical sectional view, partly in elevation, of the upper portion of the machine taken on line 3 3, Fig. l. Fig. 4 is a horizontal sectional View taken on line 4 4-, Fig. 2. Fig. 5 is a vertical sectional view of the lens support taken on line 5 5,

Fig. 2. Figs. 6 and 7 are horizontal sectional views of portions of the mechanism upper portion of the drill supporting frame j taken Online 9-9, Fig. 2, showing the preerred form of stop gage in top plan. Fig. 10 is a detail vertical sectional view taken on line 10-10, Fig. 9. Fig..11 is a detail sectional view through a portion of the operatingf'lever for the drill spindle taken on line 11--11, Fig. 2. Fig. 12 is a vertical sectional view of the upper portion of the supporting frame for the drill spindle and its guide showing a modified form' of depth gage for the drill. Fig. 1'3 is a face view of the gage shown in Fig. 12, showing a partl l of the machine upon which itis mounted in section. Figs.. 14 and 15 are perspective views of the detached lens clamping plates,

a portion of Fig. 14 being broken away to show the Avertical slots in the end thereof. Fig. 16 is a perspective view of the detached lens centering and decentering block. Fig. 17 is a perspective View of the detached base block Afor receiving and supporting the block shown in Fig. 16. Fig. 18 is a perspective view of the detached gage plate for regu lating the centering and decentering of the lens. Fig. 19 is a perspective view of'the detached locking plate for the lens centering and decentering block, shown in Fig. 16, and Fig. 2O is a face view of amodified depth gage. l i-'i This drilling machine comprises an upright standard -1- preferably of cast metal having. an integral supporting base 2'- and integral forwardly projecting arms or brackets -3 and 4 spaced some distance apart one above the other 'near the upper end thereof, th rear side of the upper portion of the standa d being pro'- vided with vertical ways -5- upon which ils mounted `a lvertically movable bracket 6- carrying a horizontal shaft -7- upon which, is mounted a pairl of idler sheaves -8- for receiving aE driving belt (not shown), said bracket being clamped in its adjusted position by one or morebolts 9, as shown more clearly in Fig. 3.

The forward ends of the arms -3- and -4 are provided With vertically alined journal bearings -10- for ,receiving a vertically disposed revoluble 'drill spindle v1l-f having its lower end provided with a socket -12- in which a drill 13- is secured by means of a set screw -14-, the

upper end of said drill spindle being jour# naled in a yoke -15- which is disposed 'some distance above` the upper arm or A pulley 18f is secured by'a set screw 1Q- to the intermediate portion of the drill spindle ,-.11- between the arms or.

brackets 4B- and 4.- and is adapted to beI driven by the belt previously mentioned which passes around the sheaves -8- and is adapted to be connected to any available source of power, not necessary to herein illustrate or` describe.

'.Wm'c balde/'.Suitable means is provided for supporting the lens in a horizontal plane or at ri ht angles to the axis ofthe drill s indle and an ang e above or below such orizontalposition or at diierent an les relatively to the axis ofthe drill spin e according to the contour of the lens; (that is, whether plain ortoric), and also for adjusting the lens horizontally to diierent angles so as to drill the same in the major axis 'or at-either side thereof. This lens holding means, forming the subject matter-of a dlvisional application No. 757,326, iledHMar-ch 28, 1913, comprises a bracket 20;- having a rearwardly projecting spindle 21- journal'ed in a alsofor su portin vit at y suitable bearing -22- in the intermediate portion of the standard -1- soA as to enable the bracket to be adjusted rotarily or tilted vertically to different angles. ,The f '95.

front end of the spindle 21- at its junction withthe bracket T22-pis enlarged to form an annular shoulder Q3- abuttin against the adjacent face of the standar 'l with the Shoulde -23- Aholds the-Spindle and bracket in operative position against axial movement. The journal bearing for v the bracket 9.0 is located aisuilicient distance to the rear of the drill spindle to af` ford ample clearance for the manipulation of the lens as -ain the lens clamp hereinafter described, the axis of movement of' theA bracket 20? being disposedin the same vertical plane from front to rear as,"

that of the drill spindle and 'also in ap# proximately the same horizontal plane as the lens rest presently described, said bracket being held in its adjusted position by a set screw -25- Fig. 4. The object of this vertical angular adjustment of the supporting bracket -20 of the lens holder is to enable the portion of the lens which .is to be drilled to be brought into a horizontal plane at right argles to theA axis Vof the drill spindle either in the major axis or at either side thereof.

The bracket --20-- extends downwardly from its supporting spindle 5.21 and is provided with a forwardly projecting hori zontal offset 20w underlying the drill Spindle transversely of the axis thereof for receiving andk supporting a base blockl extendlaterally a greaterv distance to one side' (preferably the left-hand side) .of the exis of the drill spindle than to the other side so as to a'ord ample support for the;

adjustable lensl clamps in drilling the lens yclose to the rightfhand edge thereof, said base block being provided with a raised porsome distance apart to rforni an intervening relatively shallow recess --32- for receiving and guiding a horizontally adjustable drill Lcentering and de-centering gage plate shown *Y more clearly in Fig. 6, the

, vintermediate portion of the rib 31` lbeing cut away to form a recess -Sbtm in which `the operating arm as -35- of the centeri1 and cle-centering plate is movable.

he front side of the raised portion f-29--- L of. the vbase block -27- is lprovided with a laterally projecting lengthwisel rib 456e having 'graduations -,37- enacting with anindexen the operating arm 'of the [plate -33k to indicate the point atv which the lens is to be drilled relativelyy to the major of such lens. 'For this pur? pose:A ,the right-hand end of the gage plate -33 is provided with a 'V-shape slotA B8-fog receiving a stud or stop pin -39-in a superposcd laterally'swinging drill centering block -JlOe which detachably mounted on the upper side of the base block 27- to, swing horizontally or later- `against upward displacement when in opi the righthand end et the raised portion 29ei's provided witha central semi-circular journal bearing -4lf-e seine. distance tothe leftlian'd sido ot the axis ofthe drill sgiiindle having its lower end enlarged or muriel it ir interlofllnng enga-gement with a ioni-1 l` sind wir@ projectingdowns wordly from. the underside of the. centering block --/lO--, the, lower end of'the kstud having an enlarged: semi-circular iiailg'e litting in the enlarged portion ofthe journal bearing elm-sof as to hold the een erative position. The opposite or left-'hand end ef the base block w27 is providedwith a horizontally extending transreise 'groove Hei concentric with the anis vot the ljournal bearing -41- for receiving a toothed rack 44- on the adjacent end 'of the centering block 4440*, saidY rack being also concentric rwith the axis of the journal bearing -4 .l-. The left-hand end of the raised portion -29- of the base block -27- and correspondin end of' the lcentering block v`-flO-- are a so concentric with the axis of the journal bearing tlf- 'said end lof the centering block e0-, being-extended under and downwardly across the corresponding end of the raised .portion #-29- and preferably extends from side to side thereof. The groove -4- 'in which therack -etis movableis-opcn at'both ends so as to allow the centeringlblock -40- to be rocked laterally about .the axis yof the bearing 4lso as to disengage the centering block from the base block -27-when the gage plate *3S- is moved to the .leftout of the path of the stop pin 1-39. 1

- A locking bolt 4G- is slidably mounted in a lengthwise recess -.-l7- inthe raised perdone-294 of the base block -27.- and is normally spring pressed into engagement Y with the teeth of the rack 4A- by a spring and may be forced inwardly against the action of the springby. means of an eX- tcrnal hand-piece or knob -49-, as shown in Figs. 5 and G. This locking member -4f'- isfitted with an easy sliding fit in the slot 4T-f between the baseofnsaid 1slot and 11n-"- dersideof the gage plate with suiicient clearance to prevent the shifting of the gage block when the locking bolt is operated. In like manner the gage block ismounted with an easy sliding lit between the-upperfi'ace of the base block '-27- and lower face oi: the centering block -40- and its operating nrni *35+ is offset longitudinally and provided with a linger piece -555- by which tliefgage block may be moved'along thc graduati ons -37- relatively to the stop pin 394-2 The portions of the gage block-33- at opposite sides of the lhshape slot -38- constitute stop .faces converging `'from the inner end toward the opposite end of the plate, the point of convergence also forming a limiting stop fitting closely against the pin 39 for locking thoicentcrin'g blocls:

-l0--- so as to drill thelcns on the center or major axis and when the gage plate -'-ffi?- isin this position, its index registers with the Zerograduntion 3T-1 These in` clincd stop'faccs are disposedl at the sameangle with and at opj'iosite'sides of a plane drawn through theY axes of the bearing "--lleand drill spindle when the centering block is in its normal position for drilling in 'the major axis of the lens and have stepped bearings -3I3-.

By shifting they gage block to the left a predetermined distance indicated by the i graduations -3'Z- and lwithdrawing the locking boa 'f-Jie'-, the centering 1010er with the lens thereon may be rocked laterallyabout its axis until limited by the stop pin -39v engagingone of the stepped ybearingsofthe gage plate,'thereby brmging the lens into v.position to drill part way through it such predetermined distance to one side of its center or major axis, and `with the same settin of the gage plate, the lens maybe inverted on the holder and'the centering-block.40 rocked 'in the opposite direction until again limited by the stop i pin 39-, thereby bringing the previously- ,y the holder through the lens.. In like mandrilled part of the holder in exact alinement with the drill ready to finish the drilling of nei the gage plate 433- may be adjusted for drilling the lens at any predetermined distance indicated by the graduatibns 37-f at either side of vthe center or major aXis with the assurance that the drill holes from opposite sides of the lens will always be in exact alinement with as ingle setting of the gage plate. i

b uitable lens clamping plates 150- and' -51- are slidably mounted upon the upper face ofthe centering block 40- and each is provided with apair of roller studs 52- and ,-553- for properly centeringl the lens with'i'ts major axis in a medial line lbetween the pins of each pair. These clamping lates --50-.ar1d l-51fare slidably' A inter ocked' with the block v-et0,- so as to be easily and quickly removed when desired, and for this purpose "the clamping plate *50- is provided with a head -544-- and n longitudinally extending arms -ozfispaced l some distance apart and terminating m upstanding flanges 56,- upon which the lens clamping studs -52-zA are mounted, `the arms 55- being adapted to slide in lengthrwise grooves -59- in opposite sides of theV I centering block A0- The outward sliding movement of the` lens-clamping member -50-1is limited yby a4 stop pin -40. The other lens clamping plate -51'-`` is slidably mounted upon the upper face of kare movablc.-

'the centering block -f'gfiO- anc is provided with opposite longitudinal flanges +60- extending downwardly at the.;y sides ofthe block -t0- and arms -55- of the` clamping plate -5OL, said ianges s-.60- being provided with' inwardly projecting lengthwise ribs '61,- underlying ithe opposite'k longitudinal arms -55- along which they 63'- :shown more clearly in Fig. 7 These `springs serve toconnect the lens .clamping 'pla.tes,; '-50- and ,51-` and are preferably arranged in lengthwisek grooves in the adjacent faces of the' clamping member 50+ and block 4D- the inner` ends'of the springs being attached to pins m64- on the clamping plate -5O--,4 while the'outer' ends of the sp1-ings are attached to suitable rods ,G5- rwhich enter the slots ,-62-

and are provided with heads -fG- engagin'gtlie outer end face of thelens clamping member --51.- so that the springs normally tend to draw the clamping members -50- [and -,5l-- toward 'each other t'hold their with the perimeterof the lens as -`af-, F ig; 5. These studs are not only free to roll jupon their supportingpins to reduce r` fric tion but are preferably removable to permit These'springs G3-,are located in registering lengthwise grooves in the inner faces of the arms m535-- and adjacent facesjofthe block -40` equi-distant fromk and at opposite sides of the longitudinal `center of said block so as gto move the lens clampingmeln-v bers in exact parallelism With said longitudinal center and Wherefore, parallel with the major axis of the lens to more accurately center the lens on the support, the outer ends 'as i of ,the springs-6,3-' and attaching rod 65 apertures in the adjacent ends of .the clampingplates -50-arid -51--. These clamp-4 ing plates are drawn under yieldingr sure toward an edge limiting stop -67`b means of' a spring `-68- to holdthe edge i of the lens fi-LI against said stopduring,

the drilling operation. AThe spring #-68- being passed through registering' Pres:

openings in the block ,-40- and outer ends of the clamping members -50- and -51- and has its inner end attached to a sliitable fastening member (S9-and its outer end connected to an attaching member -70 similar to the attaching member -66',in that its outer end is provided ,with ahead -71 engagedl with the outer end face taching member"70 is also seated-in a slot `*72* in the outerfend of the clam ing membe1-5land opens from the bo tom thereof.` These open-sided slots for receiving the attaching ,members '-66- and -7 1 5 permit the clamping plate 51;- to be removed without discngaginlg the springs @-63% and -GB-from their respective fastening members 64- and-69.

The upper faces of ythe lens rclamping members -50- and 5ladjacent the posts -52- and 53- are disposed in the same plane parallel with the outerA face of `the yblock -40-4 and Aguides along which said clamping members are adapted to move.

them to be replacedby new ones Wh'nfworn.'

105 is centrally disposed` within registering Y mareas When inserting a lens between the clamping pins 52- and E53-1 the clamping plates -50-- and -51- are drawn apart by hand against the action of the springs '-63- a suii'icient distance to allow the lens to enter between the -pins and when 'the clamping members are released, said springs automatically draw the clamping members toward each other to cause the pins 52- and to engage the perimeter of the lens and hold it in operative position upon the clamping plates. Y

The ,springs ,-63- and ,-68*l are com-V paratively light'and under light tension just sullicient to draw the lens clamps toward each other with suflicient positiveness to center and hold the lens and to carry said lons into engagement with the stop pin --67-, but it is desirable to provide some means.- for temporarily holding the lens clamps some distance to the left of the ,drill spindle during the placing of the lens be- ,tween the clamping-pins, an'd for this purpose we have provided the rear side of the clamping member -51 with a slot`57 -in which is pivotally mounted a holding pawl or detent .-`-58- adapted to engage the adjacent end face ofthelens centering and This detent is shown moreclearly in Fig, 4 and consists of a lever centrally pivoted to the adjacent side of the lens clamping plate -51- with opposite ends thereof disposed at anangle to each other so that when in its unlocked position, the locking end will project beyond the back face of the clamping plate 5lto be engaged by the ngers to press it to its locking position when the lens clamps are drawn "back, and when in its locked position, the

opposite end projects beyond the back 'face of the clamp. -51- to be engaged by the lingers forunlocking, the lower end of the pawl being adapted -to engage a shoulder -58-4 onl the left-hand end of the block The standard 1 is provided with a forwardly projecting integral arm some distance below-the lower arm '-3- for supporting 'the edge stop -67- and a plate Y6- which is -secured to the underside of the arm -75-m and extendslaterally across the axisoi and under the `drill -+l3- and is provided with an aperture -77- in which is loosely mounted a lens rest -78-.. This lens rest preferably consists of a cylindrical pin'or postcoaxial With the drill spindle and drill and provided with a conical upperY end and anenlarged lower end forming ar head -7t-- having'a roundinglower bearing face 80g which is concentric with the producedl axis of the supporting spindle 2l for' the bracket -20- and is adapted to bear against the upper face of the lens centering block -AO-- The upper face of f the block -AO- therefore forms a support Vposite or frontend wit for the -lens rest -78'- to hold it in operative position in axial alinement with the drill spindle and at the saine time permits the block 40- and its supporting bracket 59.0-n to be 4tilted vertically to diferent angles 4without disturbing the position of the.v

lens rest or post -7S which always remains in axial alinement with the drill spindle the object being to afford a firm bearing 'for the portion of the lens which is, to be drilled during the drilling operation.A

The upper lens bearing face of the lens rest 78- is disposed approximately at the y intersection Aof the produced axes of the spin- "justable toward and from said axis to gage the distance at which the lens is to be drilled from the edge thereof.

The stop pin 67 is preferably mounted in an externally threadedv sleeve '67- which is screwed in a threaded opening --80- in the arm -75- and is provided with an operating member -8lby which the sleeve and pin may be adjusted toward vand from the produced axis of the drill spindle, the' neriphery of the operating member-Slbeing graduated to register With a suitable index on an adjacent projection -82 ofthe arm 75-. The inner end of the stoppin -67- is preferably flattened and arranged edgewise vertically and is held in this' position byineans of an angular locking key -83- having one end inserted in the projection -827-`and its other endl119 passed through an aperture in the outer end of the stop pin'as shown more clearly in Fig. 4. The projection M82* preferably consists of a screw engaged with a threaded4 aperture in the arm -75 to afford means for-slightly adjusting the stop pin when necessary to harmonize the reading of the graduations on the'operatin-g member 81 with the corresponding distance of the stop vpin from the produced axis of the drill spindle. f

DrzZZ controlling meansf-S'uitable means is provided for moving the drill spindle and drill axially s o as tod-rill the lens part way through under yielding pressure, 'and for this purpose we have providedvalever 90- which is .pivoted at its rear end at -91- to one side ot the upper portion ofthe standard land is rovided at its o ii' asuitable hand e -92- by .which it may depressed or raised if desired. -The drill,v spindle and its supporting frame including the guide rod tions with'the drill away from the lensrest .-78- by means of a coil spring 9S-- encircling saidy guide rod #1G- between the I arm -3- and suitable pin or shoulder -94- 'on the `rod -16-. A .rock arm -96- is f lulcrumed on lthe same. pivot ,-915- co-axial with the lever -.90- in close proximity thereto and is provided' with a forked end engaged with the pin -9-1- to reciprocate the drill spindle audits supporting frame as the lever -90- is operated in drilling a lens. The lever -90- is yieldingly connected to the rock arm- 96'- 'through the medium of a spring 974- and bell crank lever -98-, the latter being pivtween the operating lever -90- and 'drill toy ot'ed at -99 to upstanding ears 1.00- on the rock arm and is provided with a rearwardly projecting apertured heel -101- for receiving an adjusting screw .'-102- by which the lever -98- may be adjusted to vary the tension of the spring The object of these connections bespin'dle is to enable the drill te be'brought l into drilling engagement with thelensunder a yielding and more uniform pressure and without liability of breaking thelens.

The normal tension of the lspring --97- is just sufficient to carry the drill frame down to its drilling position against the action of the retracting spring -93- when the lever --9OL is depressed for rilling a lens so that it the drill is brought into drilling engagement with the lens, the lever may be Jfurther depressed against the :action of the spring -97- without liability of causing excessive pressure or rapidity of feedvof.

be drilled to certain predetermined depths.

from one side, we Iprovide an adjustable depth-gage forming the subject matter of a divisional application No. 7 50,428, filed February 24, 1913, having diderent portions or points thereof of varying thicknesses corresponding .to the various standard thick-. nesses of lenses adapted to be brought into4 registration with a suitable stop for limiting the movement of the drill supporting 1,141,859 v l i frame .and thereby limiting the degree of' movement of the drill into l-the lensin the initial operation of drilling f rrn one side.

-The preferred form of gage shown in Figs. 1, 2, 3 and 9 consists of a hardened metal disk -105 encircling the upper portion of the guide rod 416- concentric therewith and resting loosely upon the- --upper face of the upper varm 4fof the standard -1-, said disk being provided with a plurality of, in this instance six,

steps or abutments 10G-,- arranged circumferentially around the axis of the disk in different horizontal planes, each step being gaged lto correspond toA a lens of predetermined standard thickness and is ada-pted to be shifted by rotation of the disk into vertical .alinement with a coperative stop -108 on the yoke -15- of the drill supporting, frame, said stop being preferably madein the form' of a screw .engaged in a threaded aperture in said yoke and projecting some distance below the same for con'- tact with the step which may be alined therewith as the drill supporting frame is ldepressed in the operationof 'drilling and is held in its adjusted position by aset The gage disk is provided in its underside with a series of apertures or sockets 110 one for each step-.for receiving a locking pin -111-- projecting upwardly from the upper -face of the arm -4-- to lock the disk in its adjusted position, said disk be-:

ing held in locking engagement with the pinA which encircles the upper portion of theguide rod -16- between the upper face of vthe disk and lower face of the yoke l5- In adjusting the disk, it is simply necessary to `elevatey the same by hand against the action of the spring "112- until disengaged from its locking pin -"111-, whereupon it may be rotated to bring any one oft the other steps into alinement with the'stop pin -108-. j

In F'gs. 12 and 13 we have shown a modified form of gage disk --105- as journaled upon a circular bearing -113- on a yoke -15- and provided with ang-,eccentric bearing face 11(5- fror coperative contact at any point with lthe upper end of va stop pin -108- which latter is, in this instance, screwed in a threaded aperture in the arm -.-4-- and held in its adjusted position by a set screw -109-. The side of the disk -105- opposite the cam face -116- is provided with av series of radial' slots -117- of different widths circumferentially corresponding to different standard thicknesses of lenses which they are adapted to receive, said slots constituting trial gages for determining the thickness of any lens which it may be desired to drill. That is,

the lens to be drilled is taken in hand and,

menace placed edgevvise in the notch or slot corresponding `most nearly to its thickness and then with the lens still in the slot and as aliandle the disk is rotated about its axis un# brought into' vertical alinement` lwitli the upper end'of the stoppin 1085-2-50 that when -the drill .frame 'is depressedl to bring the drill into contact with the, lens, the depth of the drillfhole will belimited by the engagement ofthe edge fof the dislr--116--.

with the Astop pine-310844. The slots 117e progressively lincrease in width circumferentially in one direction from one end to the other end ofthe'series, While the opposite cam face F116- gradually increases in lradins .in the same direction so that when a lens-is placed in the narrowest slot and brought-'against the stop +118- as p lframe, a. drill spindle movable axially there# indicated'in Fig. 13, the point in the cam face. of'least fradius yis brought into vertical alinement withfthe stop pin, thereby allowing the drill frame to move through ,a greater distance before the drill contacts with thelens than would be the case when either ofthe other slots-isfbrought into the same relation to the stop' @118eby the positioning off the lens therein and turning of the disk, the stop pin-108- 'and cam face being relatively' adjusted so as to allow the drill to enter onlypart way through the lens in the initial operation of drilling from one side after whichlthe lens is inverted and the drilling operation finished from the OPPO- site 'side in themanner previously described.

Tin Fig. 20 is showna modified depth gage in which a screw -108" may be substituted for .the scre'vsT -108- and provided` .having a circular series' of indexes or gaduations coacting with, the fixed `index ytolimit the drilling' movement o'i'the drill into the lens tocorr'espond to the index or gradz'iation on the disk or colla-r. 'This disk or` collar is preferably threaded internallyl for ref-.eivlngthc screw --1.08-an d per-Q "l vn'iitting' it to be adjusted thereon to' cause the registration oi. any oneof the grado ations corresponding to a lens of certam prescribed thickness toregister with -the fixed yindex when the screwfstop is pronezlyad ,insted to limit thedrilling of suchlens to the desired degree, the. disk being held in opevntive position by n set-screw -109.

What We claim isz'v l. ln a lens drilling machine, areciprd mitting motion from the rock arintofy the from the lother memberto the drill.

catory frame, a retracting spring therefor-,2x drill spindle mounted onv the frame to move therewith, a lever, and means actuated by tracting spring.

. i 2. In a lens drilling machine, `an axiially movable drill spindle, retracting m'eans therefor, and additional meansy for moving the lvdrill spindleagainst the action of its??? retracting means including a" spring of greater power than -saidretracting means.'y

In a lens drilling machine, a4 main frame, a drill spindle movable axially thereon, a rock arm pivoted to the frame, an 0p-0, erating lever, vmeans inclnding a springjor transmitting motion from thev l'everto the rock arm, and additional meansior transdrill spindle. i

4. In av lens drilling machine, a main on, a rock arm pivoted to the frame, an operatinglever, means including a spring for transmitting motion from the lever to theV im rock arm, additionalmeans for transmitting motion from the rock arm to the Adrill spin# dle, and means for limitingthe movement of the-*rock arm in the operation of drilling irrespective of the lever.

5. In a lens drillinginachine, means for moving a drill. axially toward and from the Work comprising', in combination, relatively movable rocking members having means for limiting their relative movement in one direction, a spring connecting said members, one ofsaid members being an operating lever, and meansA for transmitting motion 6. A. lens drilling` machine having an moving thespindle axially to feed the drill into the Woick, said'means including aflever vmovable independently of the drill spindle, v a spring connected to said lever, and con-V necti'ons between said spring vandspindle for transmitting Amovement to said. spindle es the spring is operated by the lever.

7. A. lens drilling machinehaving an axi ally movable drill spindle, independently' movable levers one of which is operated by hand independently of the spindle,( nmneel tions between the other lever and spindle fork moving the .latter axially'to itsdrillingposition, anda spring' connecting said-levers. 8. A lens drilling machine having an ally movable drill spindle, independently movable leversoneof which is' operated by hand independently of the spindld'connections between the other lever and spindle for 125 moving the latter axially to its' drilling po sitios', a' spring ecmiectin said. levers, and means fm; adjusting one et the levers relai `axially movable drill spindle. means for tively `to p the other 'to' vary the Atension :of the a-ipring.,` n

9, A lens drilling machine having an axi-A ally movable drill spindle, a lever operable at rwill independently .of the spindle, a rock arm separate from but contacting With the v lever, l connections between the rock arm and a sprin for feeding thedrill spindleinto the Wor rand manually operated means for l tensioning thespring, and additional means for stopping the feedingk mov ment of the A3 i y 1,141,859

drill lspindle by the spring when the drill lhas entered only'part Way through the lens. 20

v 11, A lens-drilling machine comprising an axially movable drill spindle, relatively movable levers, and a connecting spring between 'them yfor moving the ydrill spindle to its drilling position, one' of 'the levers being 25.

operatedby hand, andfa retracting spring for returning the drill spindle and levers to their normal positions. y y I Inwitness whereof We have hereunto set our hands on this firstday Lof Augst 1912. 3

GUsTAv A. BADER.. y CHAUNCEY vW. HOWLAND. 'VVitne'sseszv i 

